"For the past month, in part of eastern Kansas, the prairie has been burning, as it does almost every spring. On some days, you could look toward the horizon in any direction and see pillars of smoke. The plumes of pollution have traveled so far that they've violated limits for particulates or ozone in cities as far away as Lincoln, Neb.

But here's the twist: Environmentalists have come to celebrate those fires.

The story of how this happened starts with ranchers like , who runs cattle on 17,000 acres near Sedan, Kan. I found Sproul sitting on a chair in his front yard, looking out over rolling hills covered with brown, dried grass.

This is native prairie. It's never been plowed. Nobody ever planted the dozens of grasses and legumes and wildflowers that grow on this land. They're just here — God's gift to bison, and now to ranchers and their cattle."